2. Patients must have unequivocal evidence for tumor progression by MRI or CT scan. This scan should be performed within 14 days prior to registration and on a steroid dosage that has been stable for at least 5 days. If the steroid dose is increased between the date of imaging and registration a new baseline MR/CT is required. The same type of scan, that is., MRI or CT must be used throughout the period of protocol treatment for tumor measurement.